Hi all,
I've a system comprosed of two PIII machines, equipped with Znyx 346Q 4port
ethernet cards (tulip driver) which I'd like to connect together in a bonded
configuration. For various reasons, we require 2.4.0 kernels on our
machines - currently we are using 2.4.0-test9.
The setup is simple: each port on a 346Q in one machine is connected to the
corresponding port on the 346Q in the other machine via a crossover cable.
+-------+ +-------+
| |------| |
-----| Box A |------| Box B |-----
| |------| |
| |------| |
+-------+ +-------+
Problem #1
----------
Initally, after bootup, the performance of each of the four networks between
the two PCs is subpar. Transfer rates will vary from a few hundred KB/s to
perhaps a few MB/s, and the transfer time is appreciably long. This, on a
forced 100TX-FD link. After a few minutes however, things appear to settle
down, and I can achieve 11.2MB/s when transferring a large binary file via
ftp (rate as reported by ncftp). The de4x5 driver shows the same behaviour.
Problem #2
----------
I built the bonding driver, and using a copy of ifenslave.c which I found
for kernel 2.3.50, I was able to make a bonded channel. The trouble I found
is that the performance was not at all what I expected. Using the first eth
port, I achieved a throughput (FTP transfer of a large binary file) of 10.4
MB/s (11.2MB/s if set to full duplex). Using 2 ports, the performance
dropped to about 3.5MB/s. Adding a third port brings the throughput to
about 5.2MB/s and adding the fourth port only takes it up to 5.75MB/s.
The de4x5 driver shows the same drop in performance as the tulip driver.
Using the TEQL (trivial link equalizer) (instructions from the Adv-routing
howto) provides the same measurements exactly.
Thoughts?
Cheers!
Jon